Pressure-controlled diaphragm device



J. M. LARSON.

PRESSURE CONTROLLED DIAPHRAGM DEVICE.

APPLICATION FILED 050.27. I920.

1,379,709. Patented. May 31. 1921.

2- SHEETSSHEET 1.

fizz/672757 IQM. LARSON. PRESSURE CONTROLLED DIAPHRAGMDEVICEI APPLICATION FILED DEC.27. I920.

1,379,709. Patented May 31,1921.

2 SHEETS-SHEET 2.

JOHN 1V1. LARSON, 0F CI-TLI'ILMEO, ILLIIIOLS.

Substitute for application Serial No.

Specification of Letters Patent.

Patented May 31, 192i.

126,?74, filed. October so, 19216. This application filed December 27,

1920. Serial No. 433,392.

To all "whom it may concern:

Be it known that I, Join: M. Lansox, a citizen of the United States, residing at Chicago, in the county f Cook and State of Illinois, have invented new and useful Improvements in Pressure-Controlled Diaphragm Devices, of which the following is a full, clear, concise, and :;act description, reference being had to the accompanying drawing, forming a part of" this speclication.

My invention relates to pressure controlled diaphragm devices, and more particularly to devices in which there is an expansible chamber formed from a plurality of spring diaphragm cells all in communication with a source of variable fluid pressure, and in which the expansion of the chamber is used to (ontrol some regulating device such, for instance, as the damper of a boiler.

()ne of the objects oi my invention is to provide an improved spring diaphragm deice comprising a plurality of compactly arranged spring diaphragm cells in which the walls of the cells are so stressed that the diaphragm deice will positively and reliably return to zero position, without the aid of auxiliary springs or the like.

A further object of my invention is to provide a variable pressure chamber in which the diaphragm cells are capable of collasping until the walls of adjacent cells are in substantial contact with each other, and in which the different sections may be readily secured together.

A further object is the production of a diaphragm device formed of diaphragm cellsin which the tension of the walls of the cells is such as to cause an appreciable pressure to be exerted by the wall of one cell upon the wall of the adjacent cell even when the device is deflated.

A further object or my invention is to provide an improved spring diaphragm device comprising a spring diaphragm cell, in which the walls of the cell are placed under tension simply by securing the opposed diaphragms oi: the cell together.

A further object of my invention is to provide an improved spring'diaphragm device comprising a plurality of diaphragm cells in which the mere act of securing adjacent cells together will cause adjacent walls of the adjacent cells to exert a substantial pressure on each other, even when the cells are deflated.

A further object of my invention is to provide an improved pressure COIlbTOllQCl diaphragm device which will be durable and eflicient in use, and simple and compact in construction.

Further objects will appear from the detailed description to follow and from the appended claims.

ln the drawings in which two embodiments of my invention are shown Figure l is a side elevational view, partly in section, of a pressure controlled diaphragm actuator shown in connection with an angle valve;

Fig. 2 hows at a, b and 0, respectively, sectional views, showing successive stages in the forming of one of the walls of a dia phragm cell;

3 is a sectional View showing the upper and lower walls of a diaphragm cell before they are secured together;

Fig. 4; is a view similar to Fig. 3 showing a different form of diaphragm cell wall;

Fig. 5 is an axial section through several cells of the type snown in 4, the con struction being shown in deflated position; and

Fig. 6 is an axial sectional view through two diaphragm cells showing the cells inflated.

Like reference characters indicate like parts in the several figures of the drawing.

The construction shown in the drawing comprises a pressure controlled diaphragm device mounted on an angle valve 11, this valve comprising a valve casing 12, having cap or bonnet l3 threaded into the casing, with a stuffing box nut 14: screwed into the bonnet in order to adjust the packing around the valve stem.

The valve stem 15 is screw-threaded at its upper end for engagement with a bearing member 16, which bearing member is provided with a flange 16 at its upper end,

which flange is engaged by a coil spring 17 surrounding the valve stem, thelower end of the spring bearing on the stuffing box 14. The valve cap 13 has an upwardly extending cylindrical portion 20 provided with an annular groove 21 for the reception of a set screw 28 on the diaphragm chamber cage, for holding this cage in position on the valve cap.

The diaphragm device proper comprises an expansible diaphragm chamber 22, a cage 23, and a cap or bonnet 24 for holding the diaphragm chamber in position in the casing. upper'portion 25, and a lower spider portion 26, comprising a hub 27 surrounding the portion 20 of the cap 13, and through which hub portion the set screw 28 extends into the annular groove 21.

The opening in the hub portion 27 is sufliciently large so that when the set screw is loosened the spider may be slipped over the stuffing box nut 14 and the device removed from the valve without removing the stuffing box nut.

The upper edge of the cylindrical portion of the cage is formed with three L- shaped slots 29 forming part of a bayonet joint connection with the bonnet 24. This bonnet comprises a dish-shaped portion 30 for engagement with the upper wall of the diaphragm chamber, and downwardly extending circumferential flange 31 surrounding the upper portion of the cage and proenlarged portion 39 of the-bonnet.

vided with three pins 32 for engagement with the slot 29. These pins may be secured to the flange by riveting as shown at 33. Above and at one side of one of the pins 32 is a locking nut 34 threaded through the flange and so located with respect to the pin that when the cap is moved to its locking position the screw 34 will be in position to enter the upper part of the L-shaped slot 29.

Extending upwardly from the central part of the bonnet 24 is a cylindrical boss 35 having an axial opening 36 therethrough, enlarged at 37, forming a chamber in communication with a passage 38, formed in an This passage leads from the chamber 37 to a threaded connection 40 formed in a lateral extension 41 of the bonnet, the connection 40 in the operation of the device being in communication with a source of variable fluid pressure.

A bolt 42 extends through the opening 36, with ahead 43 and an enlarged upper portion 44 fitting closely in the opening 36 to form a fluid tight connection. The lower part of the bolt is reduced and screw-thread ed as shown at 45 and engages a nut 46 having a flange 47 at its lower end whlch is secured in any suitable manner, as by solderphragm cell.

The cage 23 comprises a cylindrical ing to the upper wall of the upper dia- This nut 46 has a reduced upper portion 48 which fits closely in the lower end of the opening 36 forming a fluid tight connection.

The head 43 of the bolt 42 and the flange 47 of the nut 46 maintain a fluid-tight con nection. The bolt 42 has an angular passage 49 therein leading from the upper dia phragm cell to the chamber 37 by means of which the diaphragm chamber is placed in communication with the source oi variable .fiuid pressure through the passage 38 and connection 40.

The diaphragm chamber comprises an upper diaphragm cell 50, a lower diaphragm cell 51, and a plurality of intermediatediaphragm cells 52. The intermediate cells are similar in construction, and adescription of one will suflice for all.

Each intermediate diaphragm cell comprises an upper diaphragm plate or disk 53, and a lower diaphragm plate or disk 54, provided with interengaging flange portions 55 and 56 respectively, secured together to form a complete cell. The upper and lower diaphragm plates are each provided with a series of concentric corrugations 59 and 60, the construction being such that when the diaphragm cells are in deflated condition the corrugations of adjacent cells are in substantial other..

F or securing adjacent cells together, each of the upper diaphragm plates 53 has secured thereto a hollow stud 61 having a flange portion 62 located inside the diaphragm cell, and a reduced portion 63 which extends through an opening in the plate 53 and each of the lower diaphragm plates is provided with a nut 64 having a reduced portion 65 which extends in the central opening in the plate. The reduced portion 63 of the hollow stud 61 is threaded into the nut 64. The hollow stud 61 and the nut 64 are secured to their respective diaphragm plates in any suitable manner, as by soldering, brazing or riveting.

Adjacent cells are secured together simply by juxtaposing them in such position that the stud 61'o'f one cell is in position to be screwed into the nut 64 of an adjacent cell and then turning one of the diaphragm cells to effect the screw-threaded engagement between the stud and nut. -The diaphragm cells can thus be secured together As will be described more in detail herecontact with each inafter the upper plate 53 and lower plate 54 are both dished inwardly, before the cells are secured together and the act of assembling the individual cells by screwing them together flattens out the dished plate, causing the upper and lower plates to move away from each other so that the cell walls are stressed and under tension even in deflated condition.

The material of which the diaphragm plates are formed maybe of any strong material, preferably metal, such as brass, somewhat harder than the material of which the stud 61 of the nut 64: are formed, so that the joint between adjacent diaphragm cells is formed by the contact of two surfaces of different degrees of hardness thus forming a fluid-tight joint without any tendency to cut the material of the contacting surfaces. The upper edge of each of the nuts 64; is provided with a number ofgrooves 66 so that the cells will be in communication with each other even when completely collapsed to a position in which the lower end of one stud rests upon the upper end of the one beneath it.

' The upper diaphragm cell 50 is substantially of the same construction as the intermediate cells 52 except that the upper diaphragm plate 67 of the former is dished to conform to the inner contour of the portion 30 of th cap 2%. The inner edge 68 of this upper diaphragm plate 67 is secured to the flanged portion 4;? of the nut 46 in any suitable manner, as by soldering or brazing.

The lower diaphragm cell is of substantially the same construction as the intermediate cells 52 except that the lower diaphragm plate is not corrugated and is preferably made of stiffer material than the other plates, to prevent upward buckling thereof when pressure is exerted on the bearing member 16 1 will now describe the construction and method of manufacture whereby the dia phragm plates 53 and 54 are initially stressed, whereby when the pressure in the diaphragm cells is released the diaphragm cells will be brought back to initial Zero position, by their own resiliency, and whereby the final movement to zero position will be positive and a substantial closing force will be exerted up to the very last movement of the diaphragm cells to collapsed zero position. 7

In Fig. 2 (0,) is shown the plain metallic disk, with the'central opening 75. In (Z2) the disk has been dished, and corrugated as shown at 59 leaving flat inner and outer pprtions 76 and 717. In (0) the outer edge or the disk has been bent downwardly forming a circumferential flange 78.

in Fig. 8 l have shown the upper and lower plates which go to make .up a. single diaphragm cell assembled in position and secured to the central studs and nuts.

The individual plates or disks 53 and 5% are dished inwardly to such an extent that in assembling them to make a complete diaphragm cell, the stud 61 of the upper plate engages the nut of the lower plate, before the outer ecges of the plates or disks are close enough together to be in proper position to be secured together. The outer edges, therefore, have to be sprung together, after which they are soldered or otherwise secured in that position permanently. This bringing together of the outer edges places an initial stress on the plates or disks tending to hold the central portions of the plates 53 and 54- toward each other, this initial stress serving to bring the plates back positively to their normal or Zero position when the pressure in the cell. is relieved.

As previously indicated, after the individual diaphragm cells have been made, they may be secured together to form a composite diaphragm cell chamber simply by screwing them together, the hollow stud 61 of one diaphragm cell being screwed into the nut 6a which is secured to the adjacent diaphragm cell.

As described above, the securing together of the plates 53 and 54 to form a. single cell places an initial stress on the plates. which causes the plates to exert a pressure on each other at their central portion, which will bring the cell back positively to zero position when the pressure is relieved in the cell. A further stressing of the plates 53 and 54: takes place when the indi *idual cells are secured together by screwing the hollow stud 61 of one cell into the nut 6% of the other cell. This follows because the plates 53 and 5% of the diaphragms are still somewhat dished (before the individual cells are joined together to form the complete composite diaphragm chamber) and this screwing together of the cells brings the plates out into substantially flat form and causes a still further stressing of the diaphragm plates. These two initial stressings of the plates of the diaphragm cells makes the built up diaphragm cell chamber in effect a tension spring which is stressed even in the collapsed position of the chamber. This will result in bringing the chamber back to initial or zero position positively when the pressure is released from the chamber:

The plates when assembled are practically flat so that the opposing faces of contiguous diaphragm cells engage practically through out their entire area, but more especially throughout the central two-thirds of the area.

The fact of the adjacent sides of adjacent cells having an extended bearing contact lessens the chance of injuring the diaphragm the cell are joined to each other at their peripheries, whereas the adjacent walls of adjacent cells are joined to each other near their centers.

In Figs. 4c, 5 and 6 I have shown a modified form of my device in which the number of corrugations is reduced, leaving a considerable fiat area 80 between the corrugations and the central opening. In addition the plates are formed with a depressed central portion comprising an angularly, downwardly extending flange 81 and a central horizontal extension 82 surrounding the opening 75. It is understood that the plates are also dished the same as those shown in Fig. 2.

In Fig. 5 I have shown a number of diaphragm cells assembled together, the central portions of the upper and lower plates of adjacent diaphragm cells being nested or fitted together, and soldered in place as shown at 83. The diaphragm in Fig. 5 is shown in deflated condition.

In Fig. 6 I have shown two complete diaphragm cells shown in Fi 5, in an inflated condition.

In the modification of Figs. 4 to 6 inclusive, I have eliminated the central studs and nuts and have thus greatly simplified and cheapened the construction. In this form, however, the individual cells are not readily detachable; but in many instances when a device ofthis kind is required, that fact is not objectionable.

IVhile I have shown several forms and described the construction, my invention may be embodied in still other forms as covered and defined by the appended claims.

This application is a substitute of my copending application Serial No. 126,774, filed October 20, 1916.

hat I claim as new and desire to secure by Letters Patent of the United. States is:

1. A diaphragm chamber comprising a plurality of diaphragm cells, each cell comprising a pair of oppositely disposed spring diaphragms, and means for setting up stress in said diaphragms such as to cause adjacent walls of adjacent cells to exert a substantial pressure on each other, even when the diaphragm chamber is deflated.

2. A diaphragm chamber comprising a plurality of diaphragm cells, each cell comprising a pair of oppositely disposed spring diaphragms, and means for setting up stress in said spring diaphragms such as'to cause adjacent dlaphragms of ad acent cells to exert a substant1al bearing pressure on each other throughout the greater extent of their prising a pair ofoppositely disposed spring diaphragms, and means for so securing together the diaphragm cells as to cause a stress to be set up in said diaphragms such as to cause adjacent walls of adjacent cells to exert a substantial pressure on each other, even when the diaphragm chamber is deflated.

5. A diaphragm chamber comprising a plurality of diaphragm cells, each cell comprising a pairof oppositely disposed spring diaphragms, and means for 'setting up a stress in said diaphragms such as to cause adjacent walls of adjacent cells to exert a substantial pressure on each other even when the diaphragm is deflated, said means comprising a screw-threaded connection between adjacent cells. 7

6. An individual diaphragm cell comprising a pair of oppositely disposed spring diaphragms, and means for setting up a stress in said spring diaphragms such that even when the cell is deflated, a substantial force will be exerted urging the central portions of the diaphragms toward each other, and the peripheral portions of the. diaphragms away from each other, said means comprising a connection between the peripheral edges of said oppositely disposed spring diaphragms.

7. A diaphragm chamber comprising a plurality ofdiaphra-gm cells, each cell comprising a pair of oppositely disposed spring diaphragms, and means for setting up a stress in said diaphragms, such as to cause adjacent walls of adjacent cells to exert a substantial pressure on each other, even when the diaphragm chamber is deflated, and such that even when the cell is deflated a substantial force will be exerted urgingthe central portions of the diaphragms toward each other, and the peripheral portions away from each other.

8. A diaphragm chamber comprising a plurality of diaphragm cells, each cell comprising a pair of oppositely disposed spring diaphragms, and means for setting up a. stress in said diaphragms, such as to cause adjacent Walls of adjacent cells to exert a cells and a connection between the peripheral 10 substantial pressure on each other, even When edges of the oppositely disposed diaphragms the diaphragm chamber is deflated, and such of the individual cells.

that even When the cell is deflated a substan- In Witness whereof, I have hereunto subtial force will be exerted urging the central scribed my name.

portions of the diaphragms toward each JOHN M. LARSON. other, and the peripheral portions away Witnesses:

from each other, said means comprising a J. H. LENIG,

screw-threaded connection betweenadjacent P. W. WASHINGTON. 

